ci: temporarily switch to alpine/edge

It has a more up-to-date nodejs version which doesn't deadlock in
"npm install".

.build.yml

@@ -1,4 +1,5 @@
-image: alpine/latest
+# TODO switch back to alpine/latest once the "npm install" deadlock is fixed
+image: alpine/edge
 packages:
 - npm
 - rsync

lib/client.js

@@ -74,8 +74,8 @@ class IRCError extends Error {
 class Backoff {
 	n = 0;
 
-	constructor(min, max) {
-		this.min = min;
+	constructor(base, max) {
+		this.base = base;
 		this.max = max;
 	}
 
@@ -86,10 +86,10 @@ class Backoff {
 	next() {
 		if (this.n === 0) {
 			this.n = 1;
-			return this.min;
+			return 0;
 		}
 
-		let dur = this.n * this.min;
+		let dur = this.n * this.base;
 		if (dur > this.max) {
 			dur = this.max;
 		} else {
@@ -134,6 +134,7 @@ export default class Client extends EventTarget {
 	autoReconnect = true;
 	reconnectTimeoutID = null;
 	reconnectBackoff = new Backoff(RECONNECT_MIN_DELAY_MSEC, RECONNECT_MAX_DELAY_MSEC);
+	lastReconnectDate = new Date(0);
 	pingIntervalID = null;
 	pendingCmds = {
 		WHO: Promise.resolve(null),
@@ -159,6 +160,7 @@ export default class Client extends EventTarget {
 
 		console.log("Connecting to " + this.params.url);
 		this.setStatus(Client.Status.CONNECTING);
+		this.lastReconnectDate = new Date();
 
 		try {
 			this.ws = new WebSocket(this.params.url);
@@ -207,6 +209,10 @@ export default class Client extends EventTarget {
 					console.info("Waiting for network to go back online");
 				} else {
 					let delay = this.reconnectBackoff.next();
+					let sinceLastReconnect = new Date().getTime() - this.lastReconnectDate.getTime();
+					if (sinceLastReconnect < RECONNECT_MIN_DELAY_MSEC) {
+						delay = Math.max(delay, RECONNECT_MIN_DELAY_MSEC);
+					}
 					console.info("Reconnecting to server in " + (delay / 1000) + " seconds");
 					clearTimeout(this.reconnectTimeoutID);
 					this.reconnectTimeoutID = setTimeout(() => {